A P F I S N

INVASIVES Newsletter of the Asia-Pacific Forest Invasive Species Network ( APFISN ) Volume 15 February - March ‘08

Threats The Asia-Pacific Forest Invasive Species Network (APFISN) has been established as a response to the immense costs and dangers posed by invasive pigra (Giant sensitive ) species to the sustainable management of forests in the Asia-Pacific region. APFISN is a cooperative News column alliance of the 33 member countries in the Asia- Pacific Forestry Commission (APFC) - a statutory body of the Food and Agriculture Organization of Sapium sebiferum – a new threat conquering the Himalayan region the United Nations (FAO). The network focuses on in inter-country cooperation that helps to detect, Rat invasions causing seabird decline worldwide prevent, monitor, eradicate and/or control forest invasive species in the Asia-Pacific region. Specific objectives of the network are: 1) raise awareness of New publications invasive species throughout the Asia-Pacific region; 2) define and develop organizational Cost-effective suppression and eradication of invasive predators structures; 3) build capacity within member countries and 4) develop and share databases and Preventing the spread of invasive species: economic benefits of information. intervention guided by ecological predictions

The role of road disturbance in the dispersal and spread of Ageratina adenophora along the Dian–Myanmar international road

Ecological correlates of invasion by Arundo donax in three southern California riparian habitats

Alien in Chile: inferring invasion periods from herbarium records

Combined modelling of distribution and niche in invasion biology: a case study of two invasive Tetramorium ant species

The invasive species assessment protocol: A tool for creating regional and national lists of invasive and non- native plants that negatively impact biodiversity

Recent books

Pest Management and Phytosanitary Trade Barriers

Forthcoming Symposia/Workshops

10 - 13 September 2008. First International Ragweed Conference. Budapest, Hungary 14 - 18 September 2008. 2nd International Symposium on Intractable Weeds and Plant Invaders. Osijek, Croatia 20 - 25 September 2008. 5th International Allelopathy Congress. Saratoga Springs, New York

INVASIVES, bimonthly newsletter of the Asia-Pacific Forest Invasive Species Network (AFPISN) is intended to share information among countries in the Asia-Pacific region on Forest Invasive Species( FIS ) and the threats they pose in the region. If you have any items of news value on FIS to share between national focal points of APFISN and more widely among foresters, agriculturists, quarantine personnel and policy makers, please pass them on to the editor - Dr. K. V. Sankaran, APFISN Coordinator, Kerala Forest Research Institute, Peechi-680 653, Kerala , India ([email protected]). The newsletter is supported by the Food and Agriculture Organization of the United Nations (FAO) and USDA Forest Service. Threats

Giant sensitive plant () Mimosa pigra, commonly called the giant sensitive plant, is a prickly, aggressive woody found especially in parts of and . It can form impenetrable, prickly thickets up to five meters high. The Global Invasive Species Database nominated this plant as being one among 100 of the world's worst invaders. The plant can interfere with irrigation and the recreational use of waterways. It has the potential to spread through natural grassland ecosystems and pastures, converting them into unproductive scrubland which can sustain only low levels of biodiversity. M. pigra is native to and Central and

South America. In its native range, the growth of the plant is controlled Mimosa pigra - Habit by native and fungal pathogens. It was introduced to the Australian Darwin Botanic Gardens in the late 1800s and is now one of about 25 - 70°C. Seeds buried deeper than 10 cm Australia's worst environmental weeds. It was introduced into generally do not successfully germinate unless from in the 1960s, intended as a green manure and cover crop brought to the surface. Typical annual production is in tobacco plantations; later it was used to help control ditch-bank about 9,000 seeds per square meter. Annual seed erosion around Chiang Mai, production per plant has been measured at up to Thailand. This weed is now 220,000 seeds under ideal conditions. Scarification distributed widely in over 51 is required for quick and uniform of countries around the globe, seeds. Germination percentages of seeds may vary including Australia, Brazil, from 75 - 94 percent. Invasion pathways to new , Colombia, India, Papua areas are mainly by agricultural activities, vehicles New and the United from infested areas, mud on birds (especially States. waders), boats, and through , people and water currents. The shrub is supported by extensive lateral roots with Mimosa pigra - flower M. pigra favors a wet-dry tropical climate and numerous fine roots that have occasional nodules. The are not as would probably not be a major problem in regions sensitive to physical stimulation as those of some other Mimosa spp. The with less than 750 mm or greater than 2,250 mm of stem of M. pigra is branched, 2 - 6 m long, has 5 ridges from which spines rainfall, except in cases of clear-cutting. Mimosa (up to 7 mm long) and bristles arise. The leaves are about 20 cm long and does not appear to grow preferentially in any soil bipinnate, with 7 - 16 pairs per pinnae; each pinnae is composed of 25 - 40 type, but is found most commonly in flood plains linear pinnules. Straight, erect or forward pointing prickles are found at and on riverbanks within soils ranging from black the junction of each pinnae and sometimes stouter, spreading or clay to sandy clay to coarse siliceous sand. Seed deflexed prickles are found between the pairs. Leaflets are linear-oblong, production and plant life expectancy are greater on 3 - 8 (-12.5) mm long and 0.5 - 1.25 (-2) mm wide. The venation is nearly black cracking clays than on the lighter and silty parallel with the midrib and the margins often bearing loams. It is common along the minute bristles. Inflorescences are sub-globose and edges of reservoirs, canals, river pendunculate, with heads 1 cm in diameter. Each head banks and roadside ditches, and contains 100 flowers, produced 1 - 2 (-3) together in the in agricultural lands and upper axils. Flowers are mauve or pink in color, calyx overgrazed flood plains. It is more is minute, laciniate 0.75 - 1 mm long; corolla about 2.25 likely to colonize and eventually - 3 mm long; stamens, 8. Flowers are pollinated by bees cause problems in disturbed and wind. The fruit is a thick, hairy compressed pod areas. This is due to the ability of containing 20 - 25 seeds; 5 - 10 cm long and clustered; mimosa seeds to establish rapidly brown in color; densely bristled and breaking Mimosa pigra - foliage on bare soils which lack transversely into about 21 (14 - 26) partially dehiscent segments, each competitive pressures from other seedlings. containing a seed, with the pod sutures persisting as an empty frame. River floodplains and swamp forests in northern The seeds are light brown to brown or olive green in color; light, oblong Australia are threatened by dense thickets of and flattened in shape; 4 - 6 mm long and 2 mm wide; are dispersed by Mimosa pigra. The weed supports fewer numbers of water and can float for an indefinite period. The seeds are extremely birds and lizards, less herbaceous plants and fewer hardy and can remain dormant for more than 15 years, depending on the tree seedlings. It prevents traditional food environment. Dormancy of seeds in the soil is broken by expansion and gathering by Aborigines on otherwise resource-rich contraction of the hard seed-coat by temperature changes ranging from wetlands. M. pigra has the potential to harm a wide number and variety of different types of primary production. If large actually increase mimosa densities by plant re- infestations occur over farmland, mimosa may threaten the health of growth and enhanced seed germination. pastoral industries by reducing the area of grazing land and the carrying Chemical methods are currently the primary means capacity of the land. Furthermore, if livestock are reliant on natural of controlling mimosa populations. Over twenty- water sources for drinking, their access to water may be blocked. As a one herbicides (applications include aerial result, meat production and income may be reduced. M. pigra may spraying, bark and stem injections and soil reduce water flow and increase silt levels, as it commonly colonizes treatments) have been tested for their effectiveness. Currently, 2,4,5-T, tebuthiuron, fluroxypyr, metsulfuron methyl, and hexazinone are the principal chemicals used to control mimosa. Six natural enemies have been released in Australia following rigorous host-specificity testing, but have not yet had any discernible effect. Four of these have also been released in Thailand. The six agents include two seed-feeding bruchid beetles, one stem- feeding chrysomelid beetle, two stem-boring and a flower-feeding weevil. The first introduced to Australia as control agents were the seed-feeding beetles Acanthoscelides quadridentatus and A. puniceus (Bruchidae) from Mexico. They were released in Australia in 1984 and 1985, Giant sensitive plant - infestation respectively, but have not attained high population water course edges. This may threaten the sustainability of reservoirs densities and have had little impact on seed and canals and any livelihoods reliant on them. For example, in production. Two stem-boring moths, Neurostrota Thailand, the weed negatively impacts rice cultivation by blocking gunniella (Gracillariidae) and mimosa irrigation inlets and also encouraging an increase in the numbers of rats (), were released in Australia in 1989; of and crabs which damage crops. M. pigra may interfere with the these, N. gunniella established readily. The young cultivation of other economically-important l a r v a e m i n e l e a f plants. For example, M. pigra is able to compete pinnules and the older with the young palm trees in immature oil palm larvae tunnel in the plantations. Common along roadsides, mimosa stems, causing them to may also increase the costs of maintaining power die. poles and cables used for electricity transmission. c o m p l e m e n t s t h e It may also decrease driver visibility, increasing action of N. gunniella by the potential for traffic accidents. tunneling stems of larger diameter. Other M. pigra presents a very different picture in its i m p o r t a n t i n s e c t s native range, where its natural habitat is mainly currently being tested marginal areas of canals, rivers and lakes, and f o r t h e i r h o s t this gives some hope to researchers looking for specificities in Mexico biological control agents. Seeds of Mimosa pigra and Australia are the In Thailand, M. pigra can serve as a pollen source for bees. The dry stems seed- and flower-feeding weevils Apion sp., and branches are often collected and utilized as firewood. The root yields Chalcodermus serripes, Sibinia fastigiata, S. ochreosa, S. 10% tannin. M. pigra is used in tropical Africa as a tonic and to treat pervana and S. seminicola. diarrhoea, gonorrhoea and blood poisoning. In , the powdered Two fungal pathogens, Phloeosporella sp. is taken with water to relieve swelling. In , the root ash is (Coelomycetes), and a rust, Diabole cubensis, sprinkled over leprous patches on the skin. The root apparently acts an severely debilitate Mimosa pigra in Mexico. aphrodisiac to some persons and a calming agent to others. The seed is Phloeosporella sp. attacks leaves, branches, main emetic and an expectorant and is used for tooth troubles. The leaf stems and seed pods, causing leaf fall and cankers of contains mimosine, an alkaloid which has medicinal properties. M. pigra the stems and leading to ring barking and die-back. can be used on the steep banks of water reservoirs as an erosion-control Diable cubensis causes chlorosis in stems and leaves, measure. resulting in premature leaf fall. Both fungi are Mechanical removal of mimosa may involve bulldozing, chaining, or attacked by hyperparasitic fungi in their native burning. A gasoline in gel form is typically applied from an aircraft to range and it seems likely that their effect on mimosa burn the stands. However, mimosa is fire-resistant and requires could be even more damaging in Australia if they additional efforts, such as chaining, to enhance burning. Fire alone may were to be introduced without their natural enemies. These fungi are under investigation in Mexico and Britain. News column

Sapium sebiferum – a new threat conquering the Himalayan region in India

Sapium sebiferum, commonly called Chinese tallow, a tree native to China and East Asia and introduced into India for multipurpose agroforestry or for the extraction of vegetable oil, is posing a new to threat to the Himalayan region by inhibiting the growth of native flora. The Chinese tallow is a fast-growing deciduous tree with a rounded or conical crown and an open, airy look. It can grow up to 12.2 m tall with a 6.1 m spread. The leaves are diamond-shaped, abruptly pointed at the tip, and 5 - 7.6 cm long. They flutter in the breeze like poplar leaves. In the fall, the leaves turn brilliant shades of scarlet, orange, yellow and maroon. The Chinese tallow- Tree with flower and fruit springtime flowers are formed in yellowish green catkins on the branch tips. The fruits are 3-lobed, brown capsules Rat invasions causing that open to reveal three white, waxy seeds that resemble popcorn. Like most members of the spurge family, broken twigs and leaf stems seabird decline worldwide exude a milky latex sap. Chinese tallow begins producing seeds at the age of three years and a mature tree can produce 100,000 - 150,000 viable seeds per year. It also spreads by suckering and cut stumps re- sprout readily. Chinese tallow is a tree that grows and spreads rapidly, is difficult to kill, and tends to take over large areas by out-competing native plants. It can thrive in well-drained uplands as well as in bottomlands, on the shores of water bodies, and even on floating islands. It is also referred to as Florida aspen and popcorn-tree, and continues to be sold in plant nurseries. These trees present a constant source of seed for continued infestation of natural areas because the seeds are transported by birds such as pileated woodpeckers, cardinals, yellow-rumped warblers, American robins, and grackles, as well as by water. While the length of time needed to deplete the seed bank is unknown, indications are that Rat attacking seabird seeds remain viable for many years with little or no loss in viability. Invasive rats on ocean islands threaten seabird The plant sap and leaves are reputed to be toxic, and decaying leaves populations. These voracious rats attack bird from the plant are toxic to other plant species. nesting colonies, eating eggs, chicks and sometimes In the United States, Chinese tallow has been grown as a shade tree and even adult birds. They have been observed preying for its brilliant fall foliage. However, the plant is now known to be on a quarter of all seabird species. Of the 328 extremely invasive and hence is now rarely used for ornamental recognized seabird species, 102 are considered planting. Seed capsules of the tree yield a wax (Chinese vegetable threatened or endangered by the World tallow) that is used to make soap and candles. Oil extracted from the Conservation Union, with predation by invasive seeds is used as a lamp fuel and machine lubricant. In parts of the species ranking among the top dangers. Seabirds American southeast, decorative wreaths are made by stringing the are important ecological actors in the oceans and on popcorn-like seeds. Honeybees make a desirable light-colored honey islands, but 30 percent of all seabirds are at risk of from the flowers. extinction. In addition, invasive rats have caused extinctions of many native land birds, reptiles, frogs To kill Chinese tallow, cut the tree down and immediately paint the and even plants. By consuming fruits, seeds and stump with a triclopyr herbicide. Good results also can be obtained by flowers, rats can change the structure and spraying the bark in a 15 cm wide band all around the base of the trunk composition of forests and alter the entire ecology with one of the triclopyr herbicides. of islands. New publications

Peter, W. J. B., John, L. S., Chris, W., Michael, A. M. and P. P. Hugh. 2008. Cost-effective suppression and eradication of invasive predators. Conservation Biology, 22: 89 -98.

Reuben, P.K. and M.L. David. 2008. Preventing the spread of invasive species: economic benefits of intervention guided by ecological predictions. Conservation Biology, 22: 80-88.

Dong, S.K., Cui, B.S., Yang, Z.F., Liu, S.L., Ding, Z.K., Zhu, J.J., Yao, W.K. and G. L. Wei. 2008. The role of road disturbance in the dispersal and spread of Ageratina adenophora along the Dian–Myanmar international road. Weed Research, 282-288.

Lauren, D.Q. and S.H. Jodie. 2008. Ecological correlates of invasion by Arundo donax in three southern California riparian habitats. Biological Invasions, 10: 591-601.

Nicol, F., Eduardo, U., Ingolf, K. and K. Stefan. 2008. Alien plants in Chile: inferring invasion periods from herbarium records. Biological Invasions, 10: 649-657.

Florian, M. S., Birgit, C. S., Jeremy, V., Keefe,D.R., Erhard, C., Christian, S., Andrew V. S., Stephen, E. W. and H.C. Ross. 2008. Combined modelling of distribution and niche in invasion biology: a case study of two invasive Tetramorium ant species. Diversity and Distributions, 14: 538-545.

John, M.R., Larry, E.M., Nancy, Benton.,Ron,H., Stephanie, Lu. And K. Terri. 2008. The invasive species assessment protocol: A tool for creating regional and national lists of invasive and non-native plants that negatively impact biodiversity. Invasive Plant Science and Management, 1: 36-49. Recent Books

Pest Management and Phytosanitary Trade Barriers. By N. Heather and G. Hallman. CABI, 2008. A significant amount of the world's economy is based upon the international trade of agricultural produce. For the producing countries, a growing concern is the potential economic and ecological damage that invasive species could cause. While threats can be decreased through the regulation of items potentially carrying invasive species, the effect of such restrictions on international trade also needs to be considered. A balance must therefore be achieved that permits the transfer of produce while filtering out unwanted pests. Drawing on the author's extensive experience, the social and financial implications of phytosanitary trade barriers are reviewed. This book offers valuable and comprehensive coverage of pest-related barriers and strategies for their implementation.

Forthcoming Symposia / Workshops

10 - 13 September 2008. First International Ragweed Conference. Budapest, Hungary. The conference will focus on the theoretical and practical aspects of ragweed infestation. Basic research, together with field applications, will be emphasized, along with laboratory, pilot, and modeling studies leading to innovative approaches. Contact: [email protected]

14 - 18 September 2008. 2nd International Symposium on Intractable Weeds and Plant Invaders. Osijek, Croatia. The primary objectives of the Symposium are: 1) to foster communication among researchers and practitioners involved in the many disciplines encompassed by invasive plants and weed science; 2) to provide a forum for the presentation and discussion of recent and ongoing research in the field of invasive plants and weed science; and 3) to encourage new investigators (especially students) in weed science and invasive plants. Contact: Edita Stefanic; [email protected]

Compiled and edited by Dr. K. V. Sankaran, APFISN Co-ordinator on behalf of the Asia-Pacific Forest Invasive Species Network. For more information on the APFISN, please contact your national focal point or the APFISN Co-ordinator or Mr. Patrick Durst, Senior Forestry Officer, FAO Regional Office for Asia and the Pacific, 39 Phra Atit Road, Bangkok. Email: [email protected]